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rpetersson
7th May 2012, 13:04
Question: When accelerating on an easterly heading in the Northern hemisphere, the compass card of a direct reading magnetic compass will turn:


I choose: anti-clockwise giving an apparent turn toward the north.

But apparently the correct answer is:

clockwise giving an apparent turn toward the north.

I have truble seeing how it can go clockwise to north? If it was going clockwise it would turn to the south.....?!:ugh:

pudoc
7th May 2012, 13:47
I'll try to explain it.

Basically, on a piece of paper draw a compass, with N E W and S. Put north at the top, east on the right etc etc.

Now imagine that to get from E to N it would be a decreasing value so it seems like anti-clockwise.

But turn that piece of paper so East is facing upwards so it's where north was. This is your easterly heading. Now you accelerate and the heading becomes more northerly. So, turn that piece of paper back so north is on top. Notice how you turnt the piece of paper CLOCKWISE. This is essentially your compass heading changing from east to a more northerly heading. We moved clockwise to get from east to north.

That's how you can work out the answer for the exam. I'll let someone else discuss the technical details as my theoretical knowledge on compasses got shat out of my brain.

rpetersson
7th May 2012, 18:01
Wow poduc you deserve a monument. Thank you soo much.